Incinerator



April 4, 1944- A. E. STILSON 2,346,054 INCINERATOR Filed Feb. 23, 1940 2 Sheets-Sheet l I v NTOR. 7/! 051/ 15'. 3/2504/ ATTORNEY.

April 1944- A. STILSON v 2,346,054

INCINERATOR Filed Feb. 23, 1940 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY. I

Patented Apr. 4, 1944 INCINERATOR Alden E. Stil'son, Forest Hills, N. Y., assignor to Morse Boulger Destructor Company, Inc., New York, N. Y., a corporation of Delaware Application February 23, 1940, Serial No. 320,265

2 Claims.

This invention relates to a combined boiler and incinerator for utilizing heat from industrial waste or the like which burns at temperatures substantially exceeding normal fire-box or furnace temperatures, and, among other objects, aims to provide apparatus of this character of practical size which has a long life and may be operated with safety.

The nature of the invention may be readily understood by reference to one illustrative apparatus embodying the invention and shown in the accompanying drawings.

In said drawings:

Fig. 1 is a sectional elevation of a combined incinerator and boiler;

Fig. 2 is a plan section thereof taken on the plane 2-2 of Fig. 1;

Fig. 3 is a front elevation of the upper water tube headers illustrating the resilient support thereof; and 1 Fig. 4 is a detail of an armored Water tube.

Many types of industrial waste develop such high temperatures on incineration that it has never heretofore been possible safely or practically to utilize the heat generated therefrom. Examples of such waste are: waste containing unrecoverable rubber; Waste containing cellulose lacquer and other nitrocellulose products; oily sawduct and other oily waste; rags containing benzine and the like; waste containing cornstarch, powdered carbon; Waste mineral oils carried in such materials as felt and paper; waste containing sugar, fats and the like. These materials burn with almost explosive violence and generate temperatures (about 3000 F., i. greatly in excess of normal fire-box temperatures) approaching and exceeding the limits of endurance of furnace refractories, and so greatly expand the gases of combustion as to require excessively large and inefiicient boiler space to handle them safely. The vibrations set up by the violent combustion and the back pressures generated by the rapidly expanding gases impose an excessive strain on the furnace structure and also cause blasts of flame and hot gases to issue on the opening of a charging or cleaning door. Aside from the danger of damage to the furnace, incineration at greater than atmospheric pressure is,

of course, impractical because of hazard to attendants and difiiculty of charging. This is particularly aggravated in the case of waste since the latter must be introduced above the fire through charging doors and the tonnage handled is much greater than for ordinary fuels.

In the illustrative apparatus, the problems attending the utilization of heat from waste of the above character have been solved by efiecting a contraction of the volume of the hot gases (before introduction into the boiler space) to such an extent that they may be safely handled in a, boiler space of practicable size. This contraction is effected in this instance by cooling the gases to approximately normal fire-box or furnace temperatures in such a way that incineration can take place at subatmospheric pressures, thereby eliminating the hazards above referred to incident to operation of an incinerator above atmospheric pressure. Furthermore, the cooling of the gases to normal furnace temperatures permits the use of economical and commercial furnace refractories.

Normal fire-box temperatures for ordinary furnaces seldom exceed 2000" to 2400 F. In rare cases with specially designed fire-boxes higher temperatures are sometimes employed. In the present apparatus the gases may readily be contracted about 25% in volume, thereby making possible the use of a boiler of practical and economical size. Such contraction represents a cooling of the gases from 3000 F. to about 2200 F., a temperature within the range of normal firebox temperatures.

In the illustrative apparatus, the cooling devices comprise a series of water tubes 19 extending upwardly from the bottom of the incinerating chamber H and inclined upwardly in the direction of travel of the hot gases. The lower portions of the tubes thus form an inclined watercooled hearth. Across the gas passage the tube spacing is increased, in the present instance, by diverging alternate tubes beginning approximately at the upper edge of the bridge wall I2, thereby providing substantial passages for hot gases from the incinerating chamber. Certain of the tubes continue their inclination and alternate tubes l3 extend vertically upward from the bridge wall (see Fig. 1) In the upper portion I4 of the combustion space the tubes again converge into a single plane as at I5 and extend upwardly to the header I6 located above the top I I of the combustion chamber. In such closely arranged relationship the tubes effectively protect the wall of the incinerator immediately behind them from the high temperatures developed inthe incinerating chamber.

Waste is advantageously introduced into the combustion chamber through a door opening [8 closed by a refractory lined guillotine door l9. As here shown, the waste is conveyed to the door on a conveyer belt 20. It may, of course, be

introduced in other ways. To protect the water tubes ID from the impact of the falling waste, the lower portions 2i thereof are armored. One form of such armoring is illustrated in Fig. 4 and comprises plate sections 22 welded or otherwise firmly incorporated in the tube.- Armored tubing of this character may be purchased on the open market. At their lower ends the tubes enter a header 23 which is advantageously free to permit deflection of the tubes under the impact of waste discharging into the incinerating chamber. The waste very often coheres in large masses (weighing several hundred pounds) which cannot be economically broken up before introduction into the incinerator. Without protection, the impact of such masses would soon damage the structure. As additional protection against the impact of such heavy masses, the upper supporting header I6 is advantageously resiliently supported. One form of such support comprises helical springs 24 located between the header and the top ll of the chamber.

For many types of waste, exceedingly high temperatures reaching about 3000 F. are developed in the incinerating chamber. In passing around the tubes H) which constitute in effect a water-cooled screen, the gases are both cooled and contracted to such volume as may be safely handled in boilers whose passages are designed for gases at normal furnace temperatures. Unless thus contracted, the gases could not be safely handled in the boiler 25 without redesigning the same to proportions which are not only uneconomical but incapable of efficient operation with gases at normal fire-box temperatures; nor could such large volumes of gases be withdrawn from the incinerator by natural or stack draft without creating back pressure, 1. e. pressure higher than atmospheric, in the incinerator. The cooling of the gases before introduction into the boiler also permits the use of economical commercial furnace refractories.

The illustrative boiler is of conventional design comprising a lower header 26 and upper headers 21 and 28. A bafiie wall 29 forces the gases entering the boiler space to travel upwardly along one set of tubes 30 and downwardly along the other set 3| to reach the flue duct 32.

Additional cooling and contraction of the gases may advantageously be effected if necessary by facing the baffle wall 33 with a series of water tubes 34 whose ends are carried by upper and lower headers 35 and 36. These tubes may also advantageously be faced with armor 31 to protect the same against erosion by the gases. Spaces 38 are provided at the ends of the baffle Wall 33 for passage of the gases into the boiler space. If desired the baffle wall may additionally be protected by air spaces 39 connected with conduit 40 by means of which cooling air may be introduced into the interior of the bafile wall.

The various headers 16, 35, etc., are appropriately connected with the boiler.

The side walls 4| of the incinerating chamber are also advantageously cooled to protect the walls and to absorb heat. The cooling means is here shown in the form of a series of water tubes 42 extending upwardly above the top of the incinerator into a header 43. The tubes may advantageously be provided with armor 45, similar to that illustrated in Fig. 4 to protect them from erosion by the hot gases and falling waste. Any other portions of the furnace wall requiring protection may also be provided with armored water tubes. In many cases where the gas flow and the fall of waste is toward the rear, the front furnace wall does not require such protection.

The water tubes advantageously protect the incinerator against accumulation of slag on the walls and other surfaces. When slag encounters a water cooled surface the slag is cooled to a point where it shatters and falls away. Cooling the walls by Water also eliminates the need for air cooling spaces in the walls which would otherwise be necessary and which would weaken the walls.

The bottom of the incinerator is provided with stationary grates 46 and dumping grates 41 by means of which ash may be discharged into a pit 48. A clean-out and inspection door 49 is advantageously provided at the grate level. Contraction of the gases by cooling advantageously reduces their volume to an extent which eliminates back pressure and permits operation of the incinerator at sub-atmospheric pressures. The incinerator may, therefore, be operated safely without danger to workmen when the charging and clean-out doors are open.

Obviously the invention is not limited to the details of the illustrative apparatus since these may be variously modified. Moreover it is not indispensable that all features of the invention be used conjointly since various features may be used to advantage in different combinations and sub-combinations.

Having described my invention, I claim:

1. Apparatus of the character described comprisirg in combination an incinerator for burning waste developing temperatures substantially above normal boiler temperatures, a boiler connected by a passage with said incinerator for utilizing the heat developed therein, an inclined hearth in said incinerator for receiving the waste to be burned therein, a waste charging opening above said hearth, said hearth being watercooled by a series of water tubes, said tubes extending upwardly across said passage and being relatively offset to provide adequate spacefor the passage of hot gases around said tubes, and. armor on said tubes to protect the same from impact of waste introduced through said charging opening.

2. Apparatus of the character described comprising in combination an incinerator for burning Waste developing temperatures substantially above normal boiler temperatures, a boiler connected by a passage with said incinerator for utilizing the heat developed therein, a series of water tubes in said incinerator extending across said passage, certain of said tubes forming a hearth for the waste, means in the upper portion of said incinerator for charging waste upon the hearth, and means for resiliently mounting said tubes to protect them against impactof falling waste.

ALDEN E. STILSON. 

